Bookbinding and the Conservation of Books
A Dictionary of Descriptive Terminology

clasps

The hinged fasteners of brass, precious metals, iron, etc., often elaborately chased, and intended to secure the covers of books, ledgers, albums, etc. They are sometimes provided with a lock, and are designed to hold the covers of a book closed, or when provided with a lock, to prevent opening by unauthorized persons. Clasps are attached after forwarding is completed except for the board papers, because by that time the final thickness of the book is known and any rivets on the inside of the boards will be covered by the board papers. Because a single clasp has a tendency to distort the boards, two are generally used, and are usually placed opposite the centers of the second and fifth panels of the spine. All metal-hinged clasps have to be made to fit the individual book, as a perfect fit is necessary; however, where the hinge consists of a leather strap, adjustments can easily be made. Stretching of the leather with use, thus causing looseness, can be overcome by making the strap of leather over vellum, which also provides additional strength.

The use of clasps appears to be as old as the codex itself. In its earliest form, which was Coptic bindings, the clasp consisted of a strap attached to the fore edge of the upper cover and wound around the book over the fore edge several times, the bone attached to the end of the strap being tucked between the strap and the lower cover. Another method, which may actually have been used more often than the strap, consisted of the plaited thong with loops which fit over bone pegs at the edge of the lower cover. A clasp of this type seems to have been used in England at least as early as the 12th century. The strap was fastened to the fore edge of the upper cover, and the end, which had a metal-rimmed hole, was taken around to the middle of the lower cover and was attached to a metal pin.

English bookbinders of the 14th century began using two straps instead of just one, something which had been done earlier and more often on the Continent of Europe. The hole and pin type was more or less abandoned early in the 14th century and replaced by clasps and catches attached to the fore edge. Initially, each clasp consisted of a strip of leather having a metal hook on one end. Later, the metal part of the clasp was the full thickness of the book and was sometimes attached to the board by means of a metal hinge. In bindings of the 15th and 16th centuries, and probably earlier, the location of the clasp is a reasonably accurate indication of the country of origin. English and French bindings usually had them attached to the upper cover with the catch on the lower, while bindings of the Netherlands and Germany had the catch on the upper cover. Italian binders often attached the clasp to the upper covers and often used as many as four clasps.

The velvet-covered books of the royal collection in England in the 15th and 16th centuries often had ornamental gilt clasps, which were often combined with elaborately ornamented gilt cornerpieces and centerpieces which helped prevent abrasion of the velvet.

The use of metal clasps began to decline early in the 16th century, probably because they could not be securely attached to the pasteboards which were replacing boards made of wood. The weight, size, and material of the books being published at that time did not require clasps, and clasps were no longer economically feasible for the normal run of books. In most cases they were replaced by TIES (1) . Clasps made of brass were still used in the 16th century for some books which were bound with boards of wood, and silver clasps and cornerpieces were often used on small Bibles and other devotional works as late as the late 17th and early 18th centuries. In certain German bindings, however, e.g., Bibles, clasps were used continuously until the end of the 18th century. his was notably true in America, for example, where almost all German-American bindings, e.g., the Saur Bibles, were issued in calfskin over wood with two heavy claps attached to the lower cover. Brass clasps were revived during the latter part of the 19th century, mainly for Bibles and prayer books, but also for photograph albums, diaries, and the like. They were often attached to metal frames which protected the edges of boards. (83 , 105 , 236 )